Tube-engaging brick



H. s. MARTIN TUBE ENGAGING BRICK Filed Aug. 26, 1921 Feb. 0

2 Sheets-Sheet 2 1 I and the like in steam boilers,'especially sec- Patented Feb. 10,1925.

or mnenwoon,

HARRY s. MARTIN, NEW

COMPANY, A CORPORATION OF DELAWARE.

v 1,525,819 PATENTOFFICE.

JERSEY, ASSIGNOR "10 AMERICAN ARCH TUBE-ENGAGING BRICK.

Application filed August 26,

To all whom it. may concern:

- .Be it known that I', HARRY S. MARTIN, a citizen of the United States, residing at Ridgewood, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Tube- En gaging Bricks, of which the following is a specification.

- My invention relates to tube. engaging brick for the construction of bafiles, arches,

tional fire arches in locomotive boilers. I aim to secure extended contact or bearing of the brick on tubes of difierent sizes, so as to make thebrick equally secure on tubes of different sizes.

Sectional fire arches of locomotive boilers are commonly constructed of aplurality of rowsof fire bricks supported on Water circulation tubes that extend fore and aft in I,

-the locomotive fire box. In these arches,

the middle rows of bricks span the'spaces between; adjacent circulation" tubes while the outside rows, of bricks commonly extend upwardly from the outside tubes to the adjacent sides of the fire box at a considerable inclination. These inclined outside or wing? bricks are especially liable .to be jarred loose and drop into the fire beneath, so that it is important for them to have an extended bearing and good friction on the water tubes that support their lower ends. Accordingly, I have herein illustrated and described an embodiment ofmyin vention with .specialfreference to its application to such wing bricks.

Hitherto, wing bricks for. sectional fire arches have been made with concavelower edges curved to fit properly oncirculation tubes of the size with which the bricks were specially intended to be used. Such bricks would not, therefore, fit properly on tubes of any other size; for if the tubes were smaller, than thesize for which the bricks single line contact with them at a point of were designed, the bricks would make a tangency, while if the tubes were" larger, the bricks would make a double line contact, at the outer corners of their concaved edges.

I. obviate this difficulty by giving to the tube engaging surface of the fire brick a conformation which adapts the brick to fit snugly against tubes of different sizes, with better contact and greater area of friction than in either of the cases above referred to.

- ture,

1?21.. Serial No. 495,586.

' In the drawings, Fig. 1 is a fragment diagrammatic cross sectional view throii gli a locomotive fire box, looking aft, showing a portion of a fire archwithwing bricks that represent the best embodiment of my invention at present known to me.

Fig. 2 is a fragmentary diagrammatic cross section of the tube engaging end of a wing brick such as shown in Fig. 1.

Figs. '3' and 4 are similar fragmentary views, on a smaller scale than Fig. 2, illustrating the behavior of the brick with tubes of difierent sizes.

The sectional-locomotive fire arch shown in Fig. 1 is of ordinary general construction, comprising two middle sections composedsof bricks 10, 1O spanned between the lower ends engage and fit snugly against the outer circulation tubes 11. 7

The tube-engaging lower end or surface 15 of each of the bricks l2 is'shown in Fig.

2 as hollowed or concaved to engage the. tubes 11. In order to make them fit snugly on tubes of different sizes, the surfaces 15 are not simply circularly concaved to a uniform radius, but are made of variant curvathey are intended to be used there will be so that for each size oftube on which an appreciable arc of'isubstantially identical radius and curvature.v As shown in Fig, 2, the lower portion A of the brick surface 15 is curved to one uniform radius .R, while the-upper portion a is curved to a smaller uniform radius r, so that these portions are adapted to fit snugly on tubes of. difi'erent sizes. The centers C and a of theseeportions A and a are preferably so located that the upper part or corner 16 of the upper portion a lies on an extension of the are A (see Fig. 2).

Referring, now, to Figs. 3 and 4, it willbe seen that when the brick 12 is used on "tubes 11 of a smaller size, the more sharply curved portion a fits the tube and makes contact with it at a multitude of points or a surface contact. When, on the other hand,

the brick 12 is used on tubes 11 of a suitably larger size, the portion 15 engages, and

tude of intermediate points in its lower portion A. In' either case, therefore, the surface 15 makes contact with the tube-at more than two points; and. on tubes of larger size, theextremity or corner 16 engages the tube 15 is simply made up of two fcircular arcs, as shown.

The usual brick with tube engaging surace cui'ved to a sin le radius so as to fit snugly on one size 0 tube 11 would make double line contact only with a larger tube 11 and so would ha ve-relatively little friction and .holding power" on the tube. With a tube of a. size smaller than those shown the brick would obviously'make single line contact 0131 WhatIc aim is: 1. A brick for sectional arch constructionhand the like with a hollowed tubeengaging surface adapted to make contact along more than two hnes with tubes of one size, and including within the limits of such engaging surface compnsmg one curved t0 fit snugl againstftubes 0 larger 1 contact a portion adapted to make contact alqn more than tww lines on tubes of smal er size.

2. A brick for sectional fire arch construction and the like having a concave tubeengaging surface of variant curvature adapted to fit ous sizes.

3. A brick for secti'ohal fi re arch'construction and the like having a concave tubesnugly against tubesfof variengaging surface including portionscurved to different radii and thus adapted to fit snugly against tubes of various'sizes.

A. A brick for sectional fire arch construc: tion and the like, havin'g a concave tubesize and a secon portion curved to fit snugly against tubes of smaller size, the outer end edge of said second portion being so located as to engage tubes of such larger size and assist in bringing the first portion rtion of the brick to bear, properly thereagainst. 1

5. A brick for sectional fire arch construction and the like with concave tube engagsurface,',':"formed on' arcs of different in radius andr' struck from different centers.

. In testimony whereof, I have hereunto-- signed my name. g

\ .HARBY s. MARTIN. 

